Anti-dust device for a combine

ABSTRACT

An anti-dust device for a combine having a feeder housing with a discharge end disposed adjacent to a threshing cylinder, the feeder housing including a conveyor for delivering crop material into the threshing cylinder. The anti-dust device includes a plate pivotally mounted transversely between the upper portion of the feeder housing and the threshing cylinder, thereby obstructing the movement of dust from the threshing cylinder back through the feeder housing. The plate is spring biased to normally assume a position in close proximity to the circumference of the threshing cylinder but is moveable outwardly therefrom by the engagement therewith of crop material rotating with the cylinder. This invention relates to combines and more particular to antidust devices for controlling the internal flow of air having dust particles suspended therein.

United States Patent De Coene et al.

[ 1 June 13, 1972 [54] ANTI-DUST DEVICE FOR A COMBINE [72] Inventors:Frans J. De Coene; Gilbert J. Strubbe,

both of Zedelgem, Belgium [73] Assignee: Clayson N.V., Zedelgem, Belgium[22] Filed: Nov. 6, 1970 21 App]. No.: 87,507

[30] Foreign Application Priority Data Nov. 14, 1969 Belgium ..741666Oct. 15, 1970 Belgium ..50525 52 us. Cl. ..130/27 R i [51] Int. Cl...A0lf 12/18 [58] Field of Search ..130/27 R, 27 E, 27 F, 27 HA,

130/27 HF, 27 JT, 29

[56] References Cited UNITED STATES PATENTS 2,367,990 1/1945 Anderson etal ..130/27 R 1,750,083 3/1930 Zaymusz ..130/27 HA 813,957 2/1906Eisenhart ..l30/27E Primary Examiner-Antonio F. Guida Attorney-Joseph A.Brown, John C. Thompson, James J. Kennedy and George C. Bower [57]ABSTRACT An anti-dust device for a combine having a feeder housing witha discharge end disposed adjacent to a threshing cylinder,

. the feeder housing including a conveyor for delivering crop materialinto the threshing cylinder. The anti-dust device includes a platepivotally mounted transversely between the upper portion of the feederhousing and the threshing cylinder, thereby obstructing the movement ofdust from the threshing cylinder back through the feeder housing. Theplate is spring biased to normally assume a position in close proximityto the circumference of the threshing cylinder but is moveable outwardlytherefrom by the: engagement therewith of crop material rotating withthe cylinder.

This invention relates to combines and more particular to antidustdevices for controlling the internal flow of air having dust particlessuspended therein.

23 Claims, 9 Drawing figures PATENTEnJun 13 m2 SHEET 10F 5 PATENTEDJUH13 I972 SHEET 2 BF 5 [NVENTORg FRANS J. DE COENE GHBERT d. STRUBBEPATENTEDJun 13 I972 SHEET 30F 5 I NV E NTOR FRANS J DECOENE GWBERT J.STRUBBE PATENTEDJUH 13 m2 saw u [If 5 I INVENTORS FRANS J. DE COENEGHBERT a. STRUBBE PATENTEDJUH 13 I972 SHEET 5 BF 5 mvNToRs FRANS J. DECDENE G\LBERT J. STRUBBE BACKGROUND OF IN VENTION In the past, the farmmachinery industry has devoted much effort to improving theenvironmental conditions immediately surrounding the machine operator.One of the most menecing conditions faced by the combine operator is thelarge amounts of dust surrounding the machine, especially in the area ofthe operators station. This dust tends to obscure the operators visionand generally contributes to a very uncomfortable and inefficientenvironment in which to work. In the case of the combine, much of thedust can be attributed to that generated within the threshing cylinderand forced outwardly through the upper return portion of the feederhousing. In order to obstruct the movement of dust from the cylinderthrough the feeder housing, the prior art teaches the use of ananti-dust plate mounted in a fixed position between the cylinder and thedischarge end of the feeder housing. Representative prior art is FrenchPatent No. 1,426,734 having a priority date in Germany of Mar. 20, I964and British Patent No. 1,096,782 having complete specification publishedDec. 29, 1967. However this teaching of the prior art has not beenentirely satisfactory and, in fact, has numerous disadvantages.

It is well recognized that in order to prohibit the movement of dustthrough the feeder housing it is imperative that the anti-dust platenormally assume a position in relative close proximity to thecircumference of the threshing cylinder. The fixed anti-dust plates ofthe prior art were limited in this respect because of the ever presentpossibility of crop material being carried along the circumference ofthe cylinder. If the fixed anti-dust plates were disposed very close tothe circum ference of the cylinder, choking or even structural damage tothe cylinder or dust plate often resulted as there was insuffcientclearance between the plate and cylinder for the carried crop materialto pass.

SUMMARY OF INVENTION Applicants have devised a spring biased, moveablymounted anti-dust plate having a tenninal edge which normally assumes aposition in close proximity to the circumference of the threshingcylinder, but is yieldable outwardly therefrom as masses of cropmaterial pass between the cylinder circumference and the anti-dustplate.

Moreover Applicants realize there are other internal factors thatinhibit the rearward movement of dust from the threshing cylinder. Oneof these is the presence of air from the straw beaters, located behindthe threshing cylinder. Specifically, the air of the straw beatersintegrates with the air of the cylinder, creating an overpressure regionabout the rear of the cylinder which inhibits the rearward movement ofthe dust from the cylinder. To correct this situation, Applicants havedisposed a deflector between the straw heaters and the threshingcylinder, the deflector having an angled terminal edge for directing theair associated with the heaters rearwardly, causing a suction effectwhich tends to draw the dust rearwardly. Also it is common to provide aclearance above the front portion of the cylinder for installation of atailings divider auger. It is quite possible that the turbulanceassociated with the tailings auger reduces the air velocity within thecylinder and consequently reduces the rear suctional effect caused bythe presence of the anti-dust plate. Therefore Applicants have provideda guide plate between the tailings auger and the cylinder to guide thestream of air around the cylinder and avoid the turbulant interferencecaused by the air associated with the auger.

It is therefore the primary object of the present invention to provide amoveably mounted anti-dust plate biased to assume a position relativelyclose to the circumference of the cylinder, whereby the plate may beforced outwardly therefrom by crop material passing between the cylinderand plate.

Another object of the present invention is to provide an anti-dust platedisposed about the feeder housing opening in close proximity to thecircumference of the threshing cylinder in order to create a pressuredifferential or suctional effect that tends to induce the dustrearwardly out of the combine.

A further object of the present invention is to provide guide meansabout the circumference of said threshing cylinder for separating theair flow therein from outside sources which tend to interfere with theflow of air in the cylinder.

Other objects and advantages of the present invention will becomeapparent and obvious from a study of the following description and theaccompanying drawings which are merely illustrative of the presentinvention.

DESCRIPTION OF THE DRAWINGS F I68. 1 3 are side elevational views of acombine with portions cut away to illustrate the anti-dust plate andother related components. I

FIG. 4 is an enlarged fragmentary side elevation view of the anti-dustplate showing a first embodiment.

FIG. 5 is an enlarged fragmentary side elevation view of the anti-dustplate showing a second embodiment.

FIG. 6 is a perspective view of the cover with the anti-dust plateaffixed thereto.

FIG. 7 is a perspective view of the anti-dust plate shown in FIG. 6mounted to the combine frame.

FIG. 8 is a fragmentary side elevational view illustrating amodification of the anti-dust plate shown in FIG. 5.

FIG. 9 is an enlarged fragmentary side elevational view taken in thedirection of F9 of FIG. 3 showing the anti-dust plate and other relatedcomponents of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENT In FIGS. 1 3, the parts areindicated in a schematical way which are directly in relation with theanti-dust equipment according to the invention. These are the strawelevator l, the proper straw elevator chain 2, cylinder 3, concave 4,beater 5, tailings auger 6, grain tank 7, and a spring biased anti-dustplate 19.

Cylinder 3 turns according to arrow P1 (FIG. 4), and is provided in atraditional way with non-reflected threshing bars; the straw elevatorchain 2 displaces according to arrow P2 and is also provided in a knownway with suitable driving elements; straw beater 5 turns according toarrow P7 (FIG. 9); the air flow which is deflected by the aforesaidplate 19, and directed in the cylinder, is reflected by arrow P3, andthe sucked air flow from elevator l is reflected by arrow P4.

As reflected in FIGS. 1 3 an antidust plate 19 is simply formed by abent plate, installed between the cylinder 3 on one hand and the openingbetween the upper part of straw elevator chain 2 and the upper part ofstraw elevator I on the other hand.

In FIG. 4, an execution is reflected of an anti-dust equipment accordingto the invention. The cylinder 3 turns according to arrow P1 and isprovided with bars 9, whilst the straw elevator 2 turns according toarrow P2 and is provided with driving elements 10. Cylinder cover 13 isdetachably installed between part 11 of the frame in which the threshingmechanism is installed on one hand and the upper side 12 of the housingof straw elevator 1. This cover 13 mainly consists of a bent plate in asuitable shape which covers the opening between the aforesaid elevatorhousing and the corresponding upper wall 11 of the frame in which thethreshing mechanism is installed. The fixation of this plate will bedescribed in detail further in the text.

At the upper end, the aforesaid cylinder cover 13 is provided with arubber strip 14, whereas .a rubber strip 15 is installed at the lowerend of cover 13. These rubber strips cover the whole width of the cover13 and are installed such that they fold away and butt with theaforesaid part 11 on one hand and with the corresponding part of theupperwall 12 of straw elevator 1 on the other hand. By the use of suchsealings which easily wrinkle, the elevator can always pivot aroundupper shaft 16.

On this cover 13, supports 17 are installed on suitable locationsaccording to the invention, in which a shaft 18 is rotatably joumalled.On this shaft, the proper anti-dust plate 19 is fixed for example bywelding, by which the free extreme end or terminal edge 20 of thisanti-dust plate forms an angle with the tangent of the cylindercircumference.

On this plate 19, which covers the whole width of the cylinder, at leastone support 21 is installed which is connected with the end of a tensionspring 22, by which the second extreme end of this spring is connectedwith a support 23, fixed on a part of the aforesaid plate 13 which issituated more to the top.

On the lower part of the aforesaid plate or cover 13, a stop 24 is fixedwith which the free extreme end 25 of the anti-dust plate 19-20 cancoordinate in order to determine the position of the anti-dust platewhich is the closest to cylinder 3, in other words the proper workingposition, while on the aforesaid supports 17, stops 26 are applied withwhich the anti-dust plate 19 can coordinate when it would be pushed tothe rear for one or another reason, in other words when it would rotateto the rear around shaft 18.

The function of the anti-dust equipment according to FIG. 4 is verysimple and as follows: The dust movement is directed according to arrowP1 due to the fact that this dust moves with the turning direction ofcylinder 3. This dust will bend over when it comes in contact with theanti-dust plate 19-20 by the presence of part 19, on one hand, and part20 on the other hand, whereby the dust has a movement directionaccording to arrow P3, in other words through cylinder 3. When straw forexample turns with the cylinder, plate 19 will deviate by turning aroundshaft 18 up to the moment that it butts the stop 26. At this moment,there is enough clearance between the cylinder circumference on one handand the anti-dust plate on the other hand in order to feed the conveyedmaterial so that there will be no deformation or rupture of theanti-dust plate l9-20 and cylinder blocking is avoided. As a matter offact, one or both stops 24 and 26 can eventually be made adjustable bywhich the distance between the cylinder circumference and the anti-dustplate can be adjusted. Such an adjustment can for example be formed in avery simple way by applying an adjusting screw in one or both stops 24and 26.

Because the air flow, according to arrow P3 has a high velocity, therewill be a reduced pressure in the supply opening of the elevator causedby the shape of the anti-dust plate and the fact that the latter isclosely installed to the cylinder circumference by which the dust,present in this clearance is sucked according to arrow P4 in thethreshing mechanism so that the dust movement towards the header by thestraw elevator chain is avoided. By means of tests, one has experiencedthat plate l920 in order to obtain this suction operation must beinstalled close to the cylinder circumference which was formerlyimpossible because of the previous mentioned reasons. Indeed, it isquite possible in this execution to make the distance very small betweenthe free end 20 of the antidust plate and the cylinder circumference 3without the presence of the above-mentioned disadvantages as it was thecase with the traditional machines.

Another execution is reflected in FIG. by which the aforesaid tensionsprings 22 are replaced by tension springs 28, for example two. Thelatter are installed in a closed bushing 29 which is secured on thelower part of the aforesaid cover 13, The springs 28 press with one endagainst the upper wall 30 of such a bushing and pass through a suitablepassage 31 in the aforesaid corresponding part of cover 13 in order topress with their second end on part 25 of anti-dust plate 19-20. Thisplate is also fixed in this case on shaft 18 which is installed insupports 17 on which stops 26 are applied. As a matter of fact, shaft 18can be rotatively journalled in the straw elevator housing 1 or in thecombine frame.

These springs 28 continuously press the anti-dust plate towards thecylinder by which this movement is limited by the head of bolts 32installed through the springs and which are provided towards their freeextreme end with a hand grip 33.

The bolt body 34 is secured on a specific location towards bushing 29 bymeans of a counter nut 35. In this way, it is provided that the locationof the bolt head 32 is adjustable towards bushing 29 so that thedisplacement of the anti-dust plate 19 is made adjustable in thisrespect. One also obtains in this way, that the springs are completelyinstalled outside the threshing mechanism housing. The hand grip 33 onlyaims at simplifying the installation and disassembly of cover 10.Finally, a guide plate 36 is installed to cover 13 by which a continuoustransition is obtained between the cylinder cover 13 on one hand and theanti-dust plate 19-20 on the other hand so that material accumulation isavoided between the anti-dust plate and cover 13.

In the execution variant according to FIG. 8, an extension 37 isinstalled on the anti-dust plate 1920 which is provided with a part 38directed upwards, by which it is obtained that the free extreme end ofthis part 38 replaces the aforesaid stop 26.

Finally, the stops 26 and 38 assure that the anti-dust plate 19 does notget in touch with elevator chain 2, particularly with the drivingelements 10.

The installation and removal of the aforesaid cover 13 is also verysimple and as follows: Extensions, respectively 39 and 40 are applied onthe rear side of plate 13 which can coordinate with holes which areinstalled in the concerned girders 41 of the machine in order toautomatically install the latter in the right place during theinstallation of the cover while the proper fixation is carried out bymeans of eye bolts, wing screws or the like, respectively 42 and 43 ofwhich the bodies are installed through the holes, respectively 44 and 45in cover 13.

The function of the anti-dust plate 19-20 is always the same with adifference that only the disposition of the retracting springs, on onehand and the disposition of the stops of such anti-dust plate, on theother hand differ in the described executions. In this way, one obtainsan anti-dust plate which can closely be installed to the cylindercircumference without the risk of crop accumulation, deformation orrupture of specific parts and by which this plate cannot come intocontact with other moving parts of the combine, especially the cylinderand/or straw elevator chain.

Finally, the shape and the installation of an anti-dust plate cause areduced pressure at the location of the straw elevator supply opening sothat the dust in the elevator is also sucked in the machine.

With particular reference to FIG. 9, the straw beater 5 caused by arotating air flow which in case no precautions are taken, is directedaccording to arrow P5 because such an air flow is conducted along thebottom of grain tank 7. By the presence of such an air flow P5, we havean over-pressure in the location of the rear half of cylinder 3, bywhich the speed of air flow P3 is obstructed as well as suction P4 as aconsequence of this.

In order to exclude this obstruction, one foresees according to theinvention in front of the straw beater and especially between thisbeater, cylinder 3 and grain tank bottom 46, a deflected plate 47 whichis fixed between the sides of the frame of the combine, by which thisplate shows a bent lower wall 48 to which a strip of elastic material49, for instance a strip rubber is fixed. The free edge of this strip isapplied as close as possible to the straw beater circumference.

By the shape and the installation of this deflector plate 47, the airflow which circulates around straw beater 5 is deflected and directed tothe rear according to arrow P6, between the blades of the straw beaterby which the creation of the aforesaid overpressure is avoided as aconsequence of air flow P5. In this way any obstruction of thecirculating air flow which is caused by straw beater 5 towards air flowP3 and P4, is avoided so that the speed of the air flow P3 becomesgreater as well as the suction according to arrow P4 as a consequence ofthis.

In order to avoid the air vortexes which come into existence in thelocation of clearance 50 between the bottom of the grain tank 7 and thefront wall 51 of the combine frame, i.e., the clearance area where thetailings auger 6 is applied, a guide plate 52 is disposed on top ofcylinder 3 and behind it and somewhat underneath the aforesaid auger 6.This plate is installed about the surrounding elements such that on onehand it hinders the passage of the air flow in the direction of thetailings auger 6 by which the existence of the vortexes are voided, andon the other hand that it directs the air flow to the front anddownwards in the direction of the springy suspended anti-dust plate 19.The distance between the aforesaid plate 52, and the cylindercircumference is preferably not smaller than the distance between theaforesaid cylinder circumference and the most adjacent point of graintank bottom 46.

In this way, the vortexes, caused by the shape of the aforesaidclearance 50 in which tailings auger 6 is applied are considerablydecreased, by which the air speed according to arrow P3 is once againstepped up. At the same time, this results in an increase of the suctionforce which is exercised in the elevator housing 1 according to arrowP4. Finally, we obtain in this way that the air flow P3 and air flow P4become maximum by which all dust and chaff are kept, respectively suckedinto the threshing mechanism.

The terms, upper," lower," forward," rearwar etc., have been used hereinmerely for the convenience of the foregoing specification and in theappended claims to describe the anti-dust device and its parts asoriented in the drawings. It is to be understood, however, that theseterms are in no way limiting to the invention since the anti-dust platemay obviously be disposed in many different positions when in actualuse.

The present invention, of course, may be carried out in other specificways than those herein set forth without departing from the spirit andessential characteristics of the invention. The present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange are intended to be embraced herein.

Having thus described our invention, what we claim is:

1. An anti-dust device for a combine harvester of the type having arotatable threshing cylinder, comprising in combination: a frame; aconcave mounted within said frame; a threshing cylinder rotatablymounted within said frame; crop feeding means supported by said frame infront of said threshing cylinder and having its discharge end disposedadjacent to the threshing cylinder for feeding crop material thereto,said cylinder being operable upon rotation to sweep material conveyedtoward said cylinder by said crop feeding means downwardly andrearwardly across said concave for threshing of said crop material; andan anti-dust device mounted adjacent a forward portion of said cylinder,and above the discharge end of the crop feeding means, said anti-dustdevice having a movable edge normally biased to assume a position inclose proximity to the threshing cylinder circumference, whereby saidanti-dust device normally obstructs the movement of dust carried overthe threshing cylinder back through the crop feeding means, said movableedge being yieldable outwardly from said cylinder circumference as cropmaterial carried over the threshing cylinder passes therebetween.

2. The anti-dust device as recited in claim 1 wherein said anti-dustdevice is fixed to a rotatable shaft disposed adjacent said cylinder.

3. The anti-dust device as recited in claim 2 wherein a cover isinterposed between said frame and said feeder means and includes supportmeans affixed thereto in which said shaft is properly journalled forrotative movement.

4. The anti-dust device as recited in claim 3 wherein the anti-dustdevice is comprised of a platelike structure extending transversely thewidth of said threshing cylinder and including an edge portion angledtoward said cylinder and in the normal biased position terminating inclose proximity to the circumference of the cylinder.

5. The anti'dust device as recited in claim 4 wherein stop means areprovided for limiting the range of movement thereof.

6. The anti-dust device as recited in claim 5 wherein said stop meansare adjustable.

7. The anti-dust device as recited in claim 5 wherein said stop meansfor limiting the outward movement of said antidust device away from saidcylinder includes extension means mounted to said shaft supports.

8. The anti-dust device as recited in claim 5 wherein said stop meansfor limiting the movement of said anti-dust device inwardly toward thecylinder includes extension means fixed to said cover.

9. The anti-dust device as recited in claim 1 wherein said biased meansincludes a tension spring connected at one end to said anti-dust deviceand connected at the other end at a distant point.

10. The anti-dust device as set forth in claim 1, wherein a bushing isfixed to a cover about an opening therein and a coil spring extendingthrough said opening is compressively held between said anti-dust deviceand the end of said bushing, whereby the pressure of said coil springagainst said anti-dust device biases it inwardly toward the cylindercircumference, said cover extending between said frame and said feedermeans.

11. The anti-dust device as recited in claim 10, wherein a bolt assemblyis axially disposed through said coil spring and bushing and extendsthrough said anti-dust device, whereby the normal distance between saidanti-dust device and said cylinder circumference can be selectivelyvaried.

12. The combination as set forth in claim 1 wherein additional airguiding means are disposed adjacent the cylinder circumference fordirecting the flow of air about the vacinity of the threshing cylinder.

13. The combination as set forth in claim 12 wherein straw beaters aredisposed rearwardly of the cylinder and deflector means are interposedbetween said straw beaters and cylinder for directing the flow of airassociated with said beaters rearwardly away from the flow associatedwith the rotating cylinder, thereby avoiding the high pressuresresulting from an integration of the two different air flows which wouldsignificantly inhibit the rearward flow of dusty air from the threshingcylinder.

14. The anti-dust device as recited in claim 12 wherein a clearance isformed over the upper front portion of the cylinder for housing atailings auger and wherein a guide plate is mounted between saidthreshing cylinder and said tailings auger for guiding the flow of airalong the circumference of said cylinder, thereby separating theturbulant air of the tailings auger from the air of the threshingcylinder.

15. The combination as set forth in claim 13 wherein said deflectormeans disposed adjacent said straw beaters are resilient, whereby saiddeflector means may move outwardly from the circumference of the strawbeaters in response to engagement therewith of straw being carried bysaid beaters.

16. The combination as set forth in claim 15 wherein said deflectormeans includes a terminal edge angled toward the circumference of saidstraw beaters.

17. The combination as set forth in claim 16 wherein said terminal edgeincludes a resilient material such as rubber.

18. In a combine having a frame, a threshing cylinder rotatively mountedwithin said frame, a feeder housing disposed forwardly of said threshingcylinder, a conveyor operatively contained within said feeder housingfor delivering crop material to said cylinder, and a anti-dust platedisposed transversely between said threshing cylinder and said feederhousing for prohibiting the movement of dust from the cylinder throughthe feeder housing, the improvement comprising: providing said anti-dustplate with a moveable terminal edge angled inwardly toward thecircumference of said cylinder for turning the dusty air rearwardly,creating a suctional effect which tends to force the air rearwardly outof the combine, said terminal edge being moveable outwardly away fromthe cylinder circumference as masses of crop material enter between theantidust plate and cylinder, thereby avoiding choking or structuralfailure of the dust plate, cylinder, or other adjacent components.

19. The combination as set forth in claim 18 wherein said plate isrotatable about a transverse axis spaced forwardly of said cylinder andmoveable thereabouts from a normal position closely adjacent thecylinder circumference to a position outwardly therefrom said whereinsaid plate is biased to maintain a normal position in close proximity tothe cylinder circumference.

20. The combination as set forth in claim 19 wherein said plate isspring biased.

21. The combination as set forth in claim 18 wherein the combine furtherincludes straw beaters disposed rearwardly of said cylinder and atailings auger disposed across the upper front portion of the threshingcylinder, the improvement further comprising: a deflector means mountedbetween said straw heaters and said cylinder and having a terminal edgeangled inwardly toward the circumference of said straw heaters fordirecting the air flow of the straw beaters rearwardly, avoidinginterference with the air flow of the cylinder and inducing dusty airrearwardly out of the combine; and a guide means mounted between saidtailings auger and said cylinder for separating the turbulant airassociated with the tailings auger from that of the cylinder.

22. The combination as set forth in claim 21 wherein the terminal edgeof said deflector means is comprised of resilient material.

23. The anti-dust device as recited in claim 1 wherein said crop feedingmeans is an undershot conveyor means, said antidust device beingdisposed in between said cylinder and the discharge end and upper run ofsaid undershot conveyor means.

1. An anti-dust device for a combine harvester of the type having arotatable threshing cylinder, comprising in combination: a frame; aconcave mounted within said frame; a threshing cylinder rotatablymounted within said frame; crop feeding means supported by said frame infront of said threshing cylinder and having its discharge end disposedadjacent to the threshing cylinder for feeding crop material thereto,said cylinder being operable upon rotation to sweep material conveyedtoward said cylinder by said crop feeding means downwardly andrearwardly across said concave for threshing of said crop material; andan anti-dust device mounted adjacent a forward portion of said cylinder,and above the discharge end of the crop feeding means, said anti-dustdevice having a movable edge normally biased to assume a position inclose proximity to the threshing cylinder circumference, whereby saidanti-dust device normally obstructs the movement of dust carried overthe threshing cylinder back through the crop feeding means, said movableedge being yieldable outwardly from said cylinder circumference as cropmaterial carried over the threshing cylinder passes therebetween.
 2. Theanti-dust device as recited in claim 1 wherein said anti-dust device isfixed to a rotatable shaft disposed adjacent said cylinder.
 3. Theanti-dust device as recited in claim 2 wherein a cover is interposedbetween said frame and said feeder means and includes support meansaffixed thereto in which said shaft is properly journalled for rotativemovement.
 4. The anti-dust device as recited in claim 3 wherein theanti-dust device is comprised of a plate-like structure extendingtransversely the width of said threshing cylinder and including an edgeportion angled toward said cylinder and in the normal biased positionterminating in close proximity to the circumference of the cylinder. 5.The anti-dust device as recited in claim 4 wherein stop means areprovided for limiting the range of movement thereof.
 6. The anti-dustdevice as recited in claim 5 wherein said stop means are adjustable. 7.The anti-dust device as recited in claim 5 wherein said stop means forlimiting the outward movement of said anti-dust device away from saidcylinder includes extension means mounted to said shaft supports.
 8. Theanti-dust device as recited in claim 5 wherein said stop means forlimiting the movement of said anti-dust device inwardly toward thecylinder includes extension means fixed to said cover.
 9. The anti-dustdevice as recited in claim 1 wherein said biased means includes atension spring connected at one end to said anti-dust device andconnected at the other end at a distant point.
 10. The anti-dust deviceas set forth in claim 1, wherein a bushing is fixed to a cover about anopening therein and a coil spring extending through said opening iscompressively held between said anti-dust device and the end of saidbushing, whereby the pressure of said coil spring against said anti-dustdevice biases it inwardly toward the cylinder circumference, said coverextending between said frame and said feeder means.
 11. The anti-dustdevice as recited in claim 10, wherein a bolt assembly is axiallydisposed through said coil spring and bushing and extends through saidanti-dust device, whereby the normal distance between said anti-dustdevice and said cylinder circumference can be selectively varied. 12.The combination as set forth in claim 1 wherein additional air guidingmeans are disposed adjacent the cylinder circumference for directing theflow of air about the vacinity of the threshing cylinder.
 13. Thecombination as set forth in claim 12 wherein straw beaters are disposedrearwardly of the cylinder and deflector means are interposed betweensaid sTraw beaters and cylinder for directing the flow of air associatedwith said beaters rearwardly away from the flow associated with therotating cylinder, thereby avoiding the high pressures resulting from anintegration of the two different air flows which would significantlyinhibit the rearward flow of dusty air from the threshing cylinder. 14.The anti-dust device as recited in claim 12 wherein a clearance isformed over the upper front portion of the cylinder for housing atailings auger and wherein a guide plate is mounted between saidthreshing cylinder and said tailings auger for guiding the flow of airalong the circumference of said cylinder, thereby separating theturbulant air of the tailings auger from the air of the threshingcylinder.
 15. The combination as set forth in claim 13 wherein saiddeflector means disposed adjacent said straw beaters are resilient,whereby said deflector means may move outwardly from the circumferenceof the straw beaters in response to engagement therewith of straw beingcarried by said beaters.
 16. The combination as set forth in claim 15wherein said deflector means includes a terminal edge angled toward thecircumference of said straw beaters.
 17. The combination as set forth inclaim 16 wherein said terminal edge includes a resilient material suchas rubber.
 18. In a combine having a frame, a threshing cylinderrotatively mounted within said frame, a feeder housing disposedforwardly of said threshing cylinder, a conveyor operatively containedwithin said feeder housing for delivering crop material to saidcylinder, and a anti-dust plate disposed transversely between saidthreshing cylinder and said feeder housing for prohibiting the movementof dust from the cylinder through the feeder housing, the improvementcomprising: providing said anti-dust plate with a moveable terminal edgeangled inwardly toward the circumference of said cylinder for turningthe dusty air rearwardly, creating a suctional effect which tends toforce the air rearwardly out of the combine, said terminal edge beingmoveable outwardly away from the cylinder circumference as masses ofcrop material enter between the anti-dust plate and cylinder, therebyavoiding choking or structural failure of the dust plate, cylinder, orother adjacent components.
 19. The combination as set forth in claim 18wherein said plate is rotatable about a transverse axis spaced forwardlyof said cylinder and moveable thereabouts from a normal position closelyadjacent the cylinder circumference to a position outwardly therefromsaid wherein said plate is biased to maintain a normal position in closeproximity to the cylinder circumference.
 20. The combination as setforth in claim 19 wherein said plate is spring biased.
 21. Thecombination as set forth in claim 18 wherein the combine furtherincludes straw beaters disposed rearwardly of said cylinder and atailings auger disposed across the upper front portion of the threshingcylinder, the improvement further comprising: a deflector means mountedbetween said straw beaters and said cylinder and having a terminal edgeangled inwardly toward the circumference of said straw beaters fordirecting the air flow of the straw beaters rearwardly, avoidinginterference with the air flow of the cylinder and inducing dusty airrearwardly out of the combine; and a guide means mounted between saidtailings auger and said cylinder for separating the turbulant airassociated with the tailings auger from that of the cylinder.
 22. Thecombination as set forth in claim 21 wherein the terminal edge of saiddeflector means is comprised of resilient material.
 23. The anti-dustdevice as recited in claim 1 wherein said crop feeding means is anundershot conveyor means, said anti-dust device being disposed inbetween said cylinder and the discharge end and upper run of saidundershot conveyor means.